Clutch and control



f July 31, 1945. .E1 A THOMPSON 2,380,680

CLUTCH AND coNTRL '7 Sheets-Sheet 1 Original Filed Feb... 14, `1940 20NVE/V TOR:

.\\\ I -EARL A. THOMPSON BY= im m 5&7 A TTOS I A. THOMPSON CLUTCH ANDyCONTROL Original Filed Feb. 14, 1940 July 31, 1945.

'7 Sheets-Sheet 2 July 31, 1945. E. A. THOMPSON CLUTCH AND CONTROL '7"sheets-sheet s Original Filed Feb. 14, 1940 INVENTOR EARL -A THOMPSON Lmgwf f A TTORNEY July 31 1945- E. A. THOMPSON 2,380,680

CLUTCH AND CONTROL Original Filed Feb. 14, 1940 '7 Sheets-Sheet 4INVNTOR:

A rromvfys f@ 5@ 5ML A. THOMPSON y BKQMWMQW E. A. THOMPSON 2,380,680

YCLUTCH AND CONTROL Orig'mal FiledFeb; 14, 1940 7 Sheets-Shet 5 July 31,1945.

July 31,1945- E. A. THOMPSON 2,380,680

CLUTCH AND CONTROL Original Filed Feb. 14, 1940 7 SheetS-Sheeb IX T0CONTROL LEVER ENGINE RDTTLE PEDAL INVENTOR. EARL A. THOMPSON A T TORNEYJuly 31 1,945' E. A. THOMPSON 2,380,680

` CLUTCH AND CONTROL Original Filedy Feb. 14, 1940 7 Sheets-Sheet '7selection and compel shift oi drive by the brakesI and clutches to adesired driving ratio. through measured torque capacity proportioned totorque demand. s

The interconnection of my controls with the priorly described controlsof associated primemovers and variable speed transmission and clutchunits is likewise herewith disclosed and augmented for a compoundedpower control regime yielding correlated functional speed ratio changeswherein doubly-compounded speed ratio changing effects are obtained bymechanism'providing graduated rate-of-change action.

Additional features of novelty appear in my disclosure as regards.auxiliary power supply, al-

ternate measured actuation of seiected speed ratio compelling andactuating mechanism, reciprocal and coordinate automatic controlstherefor, involving combinations oi driver will, driving conditions, andmaster selection controls capable of superseding automatically selectedspeed rat-io settings. These features involve the use of mechanismproviding a proportional torque capacity measured according to torquedemand, and will be apparent upon inspection of the followingspecifications, claimed and illustrated in the accompanying drawings, inwhich:

Figure 1 islan elevation section of the forwardneutral-reverse gearshowing the drive to the servo pump system, the lubrication porting andthe shifter mechanism for the primary shift gearing controls. v

Figure la is a similar view to Figure l of the general transmissionassembly structure with the casing broken away at the bottom.

assenso being enlarged views of the interlocking control lever systemand the valving for the front and rear units respectively.

Figure 91s of a schematic control system similar to Figure 6 embodyingmodifications of the controls and actuation members wherein a closer.

gearboxes,

coupled integration over the degree of drive is maintained by the manualcontrol elements. than in the system of Figure 6.

Figure 10 is a detailed sectional view of the manually operated controlvalve for the rear unit of Figure 9. A

Figure ll shows the differential valve of Figure e in detail.

Figure 12 is a view of the porting of the automatic pressure valve IIIof Figure 9, as in running condition.

Figure 13 is a view similar to those of Figures 6 and 7 of theinterlockinglever controls, but describing modifications by which theoperator may enforce continuous drive in third speed withinV apredetermined speed range. Figure 14 describes the modincations in thecontrols at the driver's position for the modifications of Figure 13.

Figure 15 is a representation of a modication 'oi the differentialcontrol valve of Figures 6, t

and 1l. wherein the relative pressure operated sleeve is omitted, andthe movable valve is a unitary member.

In Fig. l the vertical longitudinal section oi the transmissionstructure shows the general relationships of the gearing and drivingelements, with the forward-neutral-reverse gear unit at the right. y

The main clutch bell housing i is attached to the tr si.. ion casing 2by bolts l. Web 5 separates the forward-reverse unit from the rest ofthe transmission, which is substantially as in S. N. 45,184 notedpreceding, and shown also in section in Figure la.

The main clutch driven shaft 8 is supported i is fixed non-rotatablythereto. The splined Fig. 1b is a broken away section of the driveelements located at the lower left portion oi Fig. l.

shaft t of the forward-reverse unit pilots the forward end of shaft 2l,where thrust bearings iii and it deliver certain axial thrustsoriginating in the system ci gearing and shafting to the casing ilthrough bearing i. Thrust bearing it is in the pilot space betweenshafts B and t.

Driven shaft t carries drum il, the inner suriace of which is internallytoothed at I2 to form the input ring gear of the front unit. v.'1linwebdsupportsshaftlinthecasing. The countershaft Il is non-rotatablysupported in l and web l. The countershaft gear body 20 rotates onbearings il on the countershaft H. The first gear element I l of thecountershaft'gear body constantly meshes withinput gear v r The secondcountershaft gear element I'l is constantly meshed with reverse idlerJlsupport- Figures 5 and 5a, 5b and 5c. describe the clutch plates lt-SIand -II of the front and rear units of Figure 1a, which provide directdrive coupling. Figure 5a is a section of the externally in section inFigure la. Figure 6 is a schematic drawing of the en Vkeyed clutchplates Il and Il, such as shown control and shift actuation system asseen generally from the left side of the vehicle in which myinstallation is shown as an example:` This view'traces out-ali of thecontrol functions both manual and automatic which include the action ofthe clutch device-` noted above; Figures 7 and 8 ed in casing 2. Thereverse idler gear I-l may also be meshed with sliding 'gear Il splinedto and slidable on.splines I of shaft I. The teeth of It are meshablewith teeth 'l' of Bear Bushing Il pilots shaft I in shaftl and inte-Bral gear l. I

Thrust bearing 41, similar to Il and Il' transfers thrusts between shaft'Il and shaft Il car- .ried in the casing on" bearing It. The extension4B of shaft Ilfacts as a carrier for planets ll spindled on shafts u, asshown in Figure la.

The ton lubrication and servo pump rotors ill and |12 ofythecompoundpump assembly to be described later, are driven, one by countershaftgearbody 20, the other by shaft 8. The compound pump operatesconstantly, whenever rotational power is applied to clutch driven shaft5, or to shaft 8, by virtue of gears |13 and |14, rotating with theshafts respectively.

Shaft 2| is splined to carrier 22 of the front unit, and is piloted atthe front end in shaft 8. and at the rear in the output shaft (notshown). Ported oil passages deliver servo and lubrication oil pressureto the various units as has been described. 'Shaft 2| is the poweroutput member for the front unit. The rear unit is not shown in Figure1.

Fixed to carrier 22 are spindle shafts 23 for planet pinions 24. Pinions24 constantly mesh with the inner toothed ring I2 of drum Il, and withsun gear 25. The latter is integral with sleeve 26 rotating on bearings21 of the sleeve of carrier 22. Pinions 24 rotate on bearings 23 onshafts 23.

Governor drive parts are shown in Figure 3 in relation to the gearing ofFigure .1.

In the "rear unit the arrangement of elements is as shown in S. N.45,184, except as noted in the improvements in the present case. Theeleva- --tion section of Figure la is a schematic view of thetransmission structure according to the case noted.

In Figure la, the unitary assembly in section is given, with theidentifying parts of Figure 1 in the forward-neutral reverse unitduplicated. The so-called front unit is that one immediately adjacentthe forWard-neutral-reverse gear, and consists of a planetary, two-speedgear, brakeclutch operated, the brake applied by springs regulated byoutflow of fluid pressure, and the clutch applied by uid pressure.

Bolt 32 in Figure l is a clamping means for the members 29 and 30 of thereaction drum of the front unit as shown in Figure 1a. The web ofreaction sleeve 22 is riveted at 3| to hub 34 splined at 35 for plates33. Plates 36 are apertured to permit passage of the bolts, as in Figure5b. r

The structure is; output shaft 2|, keyed or splined to carrier 22extended to support clutch plates 33, having spindles '23 for planets24, reaction sun gear 25 being aflixed by sleeve 2-6 to brake drum 28extended at 30, and serving as a mount for presser plate 14, clutchreleasing springs 88 and plates 36. The drum 28 is recessed in cylinders1| for pistons 12 having pins 13, passage 19 opening to the cylindersfrom gland 289 to which pipe 218 leads by passage 281.`

Shaft 2| is the input member for the vso-called rear unit, and hasintegral sun gears 31 and 38 meshing with planets 43-44 respectively.Out` carrier 54 for planets 44 which constantly mesh with annulus 42rotating with drum 39 on which brake 90 may bear. A i

Fig. 1b is a partial section of the drive elements as viewed in moredetail to the left of Fig. 1 and includes the drum and clutch platemounting construction below the central portion of Fig. 1a. The clutchplates 36 are square notched as shown in Fig. 5b for the keying withstuds 32, and presser plate 14 is likewise. Thev alternate roundednotches are to permit free' space for disengaging springs 88, shown inFig.'1a. Movement of plate 14 to the right compresses springs 88 andprogressively ilatt'ens plates 36, the spaces between 36 and plates 33closing radially with increased engaging motion while the plate contactarea grows, the action building up the clutch torque capacity.

Clutch drum 59 is keyed vto rotate with shaft 2|, and is splined forclutch plates 60. Springs 89 are release biasing means for clutch 55-60,the plates being keyed to rotate with drum 39, extended at 56, in whichportion clutch cylinders 15 mount pistons 15, piston pins 11 bearingagainst presser plate 18. Passage 19' feeds from leads in gland membersimilarly to the front unitV porting, for clutch actuation by fluidpressure. The operational action of clutch 55- 60 is the same as that ofclutch 33-36.

The brakes 60-90 are similar in construction, self-wrapping beingnegligible, the arrangement being as in Figure 4. The clutch plates areso designed that a definite amount of lubricant is maintained on theengaging driving faces after preliminary engagement. In Figure 5, theinternally splined plate is shown spirally scored in a manner such thatunder pressure, excess lubricating oil squirts out at the periphery, yeta considerable volume of trapped oil remains in the score cuts, as willbe clear by inspection of Figure 5a. In the Figure la, plates 33 and 6|)are so constructed, and these are preferably of hardened bronze orsimilar material. The scores may intersect the external margin, or theinternal spline cuts; or stop short of intersection at both points. Thedesigners requirement for effective clutch area, for the needed clutchcapacity, the net coefficient of friction and for the time factor withrespect to clutch capacity will control the choice of suchintersection', the dimensions of the scores likewise being involved inboth net clutch area and in the volume of oil desired to be held. Figure5b shows the detail of clutch plates 36 and 55, externally keyed torotate with drums 28 and 39 respectively. These are preferably of steel,and preformed in conical shape, in order to assist release when fluidpressure is removed for disengagement. It has been found in practicethat multiple disc clutches under pressure have an unpleasant dragunless sufficient energy is stored in the clutch plates to break thecompressed oil nlm through progressive shear force such as afforded bythis construction. This method of release control is believed novel.

The action of engagement in a clutch such as at 33--38 is first forfluid pressure to flow in 218 and 19, Figure 1a, to move piston 12`against the conoidal disc spring action of clutch plates and releasingsprings 88.' As will be vdescribed later, the servo pumps of givenspeed-range capacity work against a resistance afforded by the brakesprings 81-31a in addition to the above noted clutch spring actions,which determine the regulated ability of the clutch as a torquesupporting mechanism.

As described thus far, the clutch will of necessity need to carry enginetorque times a design factor, and the fluid pressure range needed tofurnish direct driving torque with depend upon the servo pump net speedcomponent. Later will be explained the means whereby the clutch capacitymay be varied by changes in the torque demand and variations in ratio,yielding accommodation to driving conditions for smooth operation inwhich the net line pressure in cylinders 1|, for example, may be low forinitial drive when the clutch torque capacity requirements are low, andhigher when the requirements are higher. From these initial points, thebuilding up' of clutch pressure to maximum engagement pressure proceedson a predetermined scale commensurate with the available line pressure,conditioned by the resistances acting against the pumps.

In Figure scores 62, 63 in plate 33 are spirally cut in sections asshown in Figure 5a, wherein a predetermined ratio of contact surfacebetween the clutch plates, and the volume of oil which can be retainedin the scores, is established. In the example, the innermost land of thescores does not intersect' the internal teeth 6|, but the outermost landdoes intersect the outer edge. The scores may serve as a flat reservoirof oil, when the clutch system 33--36 is engaged. Bolt 32 is a clampbolt; for the drum parts, and is also a key bolt for anchoring plates 36against rotational motion with respect to the drum.

'I'he ratio shifting controls integral with the transmission assemblyare as follows. In the forward-reverse unit, slider gear I9 may occupythree positions; forward drive when clutched to teeth 1 of gear 1,neutral, and reverse drive when meshed with reverse idler gear I8. Yoke|00 is integral with member |04 mounted on rod |0| and controlledthrough arm |02 and shaft |03. This linkage is also shown in Figures 3and 6.

By way of illustration, in Figure 4 is shown anchored in casing 2, oneend of brake element 90. Pin 92, locked by a nut 92a, engagesthe socketof anchor piece 9|. The opposite end'93 of brake 90 is pivoted at 90a tothrust rod |90. This brake element as shown consists of a single turnWrapped so that upon actuation when the unit is operating, a minimum ofself-energising force exists. Pre-set or pre-energised springs, held offby the fluid pressure system and controls to be described, are effectiveto actuate the brake at controlled rates. The detail of the servo systemis shown in Figure 6. 'I'he brake 80 of the iront unit is identicallyconstructed, and internally arranged as in Figure 6.

Clutch 55-60 as in Figure la couples reaction drum 39 to shaft 2| toestablish direct drive in the rear unit, and brake 90 prevents rotationof drum 39 and annulus gear 42 to establish geared drive. The clutchdetail is given in Figure 5. Similarly, clutch 33-36 couples clutch drum28 to drum 34 for direct drive in the front unit',l and brake 80attached to casing 2, and worked by piston rod 280, establishes geareddrive. (See Figures 4 and 9.)

In summation, either front or rear unit may therefore be in direct orgeared drive by alternate' operation of the brake or clutchrespectively, yielding four net forward speeds, as in the followingexamples:

It should be noted that shift lever |09 -fastened to shaft |08 transfersoperator shiftermovements from the linkage at the left of Figure 6 togear 19 of Figure 1."

Front unit Rear unit Reduction Direct Reduction Dire Reduction.

. Do. Direct.

. For example, with reduction ratios of 1.5 to 1 i inthe forward unitand2.25 to 1 in the rear unit, the overall lowest ratio available would beNow if we shift the rear unit to direct, and the front unit to gearedlvdrive, We obtain a net loverall reduction of 1.5/to' 1. Direct drive inboth units yields l to 1, all elements rotating together. It is entirelyfeasible to obtain all of those ratios superimposed on the reverse drivegear ratio, but is unnecessary for passenger car purposes.

In Figure 6, recessed in cylinders 1| in ange 29 of drum 28 are clutchpistons 12, guided by pins 13 in presser plate 14. Similarly, cylinders15 in web 56 of drum 39 are fitted with pistons 16 guided by pins 11 inpresser plate 18. Drilled passages 19 lead to cylinders 1| and passages19 lead to cylinders 15.

Lubrication and servo system The main supply of transmission lubricatingoil for all three transmission units is kept in the sump 219. The maindrive for the double pump is by means of element 20 to which pump rotorgear |13 is fixed, and shaft |19. The pump is operating at all timeswhenever either shaft B or shaft 8 are running by virtue of the drivetransmitted through gears |13 and |14. The construction is shown inFigures 1, 2, and 3.

Passage 22| receives lubrication oil from pump line 220 shown in Figures9 and 12, delivering to ports 22|, 223, 224, 225, and 229, from whenceit lis fed under pressure to the various bearings and gear elements. i

Figure 2 shows the detail of the drive to the servo pump. Gear |14 fixedto shaft 8 drives gear coupling |15 in which is socketed governor shaft24| and the secondary rotor shaft |16 of lthe servo pump. For allforward rotations of shaft 8, the secondary pump assembly |80 producespositive pressure/but for negative rotations, its rotation subtractsfrom the net line pressure produced by primary pump assembly |19.

Gear |13 affixed to countershaft body 20 drives gear |11 of hollow shaft|18, which drives the rotor |1| of primarypump unit |19.

As noted in Figure 3, the primary rotor |1| Y drives idler gear |82, andthe secondary rotor |12 drves idler gear |83. For all rotations of theengine connected shaft 6, primary pump unit |19 furnishes positivepressure, even when shaft 8 revoves in reverse. `See diagram, right, inFigure The suction space |10 of the pump feeds from pipe |9I of Figure 3and delivers through' both gear discharge orifices |04 and |85 topressure space from which the main feed is delivered to ports 202 yand204 of the automatic pressure control valve v200, shown in Figures 9and12.

Pump suction is exerted at space |10, and pressure is developed as longas either of the two rotors receives drive through the described gearingpaths. Driving in reverse does effect slightly the positive net deliveryof pressure by the pump, since the pump unit driven by gear |14 is ofsmaller capacity, and may rob the other unit. The outward fiow of oil isbest seen in Figure 9 where pressure space |95 opens to passagesl |99and |91.

-Valve cylinder body |98 may be built into the casing 2 or separatelyattached. Valve member 200 moves back and forth in ported passage |99,held by spring 20| in the down position,'as in Figure 9, and lifted bylpressure furnished by the y pump through milled leads |96 .nd |91.

The valve member 200 is a ground fit in this passage |99 to form seatsbetween the ports which will now be enumerated; port 202l at the lowerposition, open to lead |96 from the pump: port 203 connected to th'eservo pressure main 238; port 204 to the transmission lubrication main220; port 205 to pump port |91; and port 206 tp the exhaust outlet valve2I'|. Stop flange 201 affords a seat for spring 20 I Valve member 200has a longitudinal passage 208 cut part way'of boss 2 I4, which in thelowermost position is clear of the bottom of port 202, for obtaininginitial pressure lift against spring 20|. Assuming an increase ofpressure in the pump, valve member 200 will rise as pressure builds upbehind abutment 2 0.

As the upper edge of 208 passes the lower limit of port 203, valvemember 200 has already exminimum causes pressure above and below boss2|t to become less than the force of spring 20|, and less than the brakespring pressure so that valve 200 dumps the oil from the servo line intothe lubrication main 22d.

At extreme operating speeds, if pump develops more than the requiredpressure, valve 200 will go to the extreme up position, with spring 20|fully compressed. At this setting, abutment 2|| is opposite the upperlimit of relief port 200.

Over pressure from lead |91 may escape direct to port 206, returning tothe transmission sump by relief valve 2I1. At high speed the reliefaction occurs whenever the pressure requirement is exceeded, but nodisconcerting change in the op- `of the leak pass 214 at low speeds forinitial lubrication.

A feature in this construction is the transfer of relieved servopressure to the lubrication system.

This prevents hunting and consequent slipping of the clutches and brakesin the transmission assembly; a useful commercial feature for avoidingexcessive Wear and heat.

YThe particular grouping of the porting of the automatic pressure valvein the present combination provides a new characteristic extending therange of utility of controls provided by the valve action. The groundfitting of valve 200 in bore |99 is sufliciently loose so that a.continuous leakage of pressure occurs. The graduated effect of thisleakage, coupled with the restriction passage 208, the relatedcapacities of brake and clutch cylinders, and the force of brakesprings, combine to yield a net response suitable for establishingchanges of speed ratio varied lby pump pressure,

For example, with not sumcient pressure in line 238 to sustain clutchingin the front and rear units, their brake springs lock the brakes toestablish low-low, or lowest forward driving speed ratio. Provided theother valve controls are set y to deliver pressure to the front and rearunit systems, an increase of pump pressure lifts valve 200 to a pointWhere boss 2 Illv blocks port 204, preced- Iing the uncovering of port205 by abutment 2| I.

Spring 20| is preset to yield for a given set of pressure conditionssuch thatwhen the valve 200 passes frominitial to running condition,there is a rapid build-up of servo line pressure at the medium lowspeeds of the pump, at which capacity is ample to operate the fluidservo motors of bothl the front and rear units.

Therefore, if the further, ratio control valving is set to admitservoline pressure from 238 to either or both of the front and rear units,the speed ratio of drive will change up to second or to higher speedratios, established by variations of pump pressure and controlledbyautomatic valve 200.4 1n this case the settings of valves |68 and |50may be considered as preselected, with actual selection determined byvalve 200. In this event, the engine speed at which the operatordetermines to drive, the ability of the engine to handle the existingload, and the resulting speed of shaft are the factors which control thecriti-r cal pressure for speed ratio upshift.

Inlet port 260 delivers fluid pressure from line 238 and line 213 tovalve |50. opening to sump, may be equipped with a selfloaded reliefvalve such as 2|l in Figures 9 and l2", for metering the rate 0f clutchrelease and brake engagement, as is obvious from the construction.Further port 269 relieves the end of valve |50, freeing the movementfrom suction, to afford a positive response of valve positioning togovernor and. operator-operated movements.

If in starting off in low-low the operator has set the handlever inhigh, valve |68 is in the upper position, and at a pump pressure forexample of 50 pounds, valve 200 has admitted pressure to line 238, whichpressure is now available to brake piston 29| and clutch pistons 16. Ina given interval, pressure in 238 will rise until brake 90 will release,and clutch 55-60 will as- '40' sume the drive at whatever pressures areexisting at the end point-of brake release with a clutch capacitycommensurate with the brake release pressure value.

At the same time the governor operated valve |50 may be in either theright or left position, depending upon the coaction of pin I i5 andlever III, and if in the right or direct drive position, the building upof line pressure in 238 will also cause actuation of brake piston 28|and clutch pistons 12 of the front unit. It-will be seen that valve 200does, under these circumstances, aiord automatic ratio upshift. If thehandlever 30| were in the low position, valve |58 would, of course, beinactive, and change-up in ratio could only occur in the front unit, bypresetting of valve |150.

Automatic downshift therefore can occur as a complement to the abovedescribed action, by movement of valve 200, the relief of pressure beingcontrolled by two means; first, through dumping of line pressure intothe lubrication line 220, and second, by reason of the metering actionof check valve 2I8 pivoted at 2I9', having metering port 221, andmounted to respond to back pressure ow toward the pump. from the servomotors, and to swing clear when the pump pressure is positive. As soonas pump pressure falls, the release rate of pressure from the servosystem is controlled by' metering .port 221, while the orilicecapacities of 204, and the valve space between 2| I and boss 2I4likewise becomes effective.

The latter expedient cushions the downshift action .by letting on theAbrake springs 91 and 81 1gradually, preventing sudden, decelerationshock oads.

Relief port 2te` sages in shaft 2| furnish lubricant to the gears ofboth the front and rear units.

`Drain out of such lubricant oil under pressure finds its way back tothe sump 2|9, the closing of the direct drive elements of the clutchrelieving the accumulated oi1 in the drums.

`The forward-reverse unit obtains oil under pressure from the passagesshown. Further lubrication of the unit is by customary dip in the H sumpoil. The compartment construction of casing 2 makes it possible to sealthe entire assembly with oil pan 23|, which acts as an oil reservoir,sealing means 2|6 providing a tight joint at all contact points.

' The use of a common sump for the gear units and the servo actuatorsyields advantages for low leakage losses, rapid re-circulation, andmaintenace of proper capacity requirements, and provides one-lillservice oil replacement. 'I'he resistance drop of the circuit of oilpressure mains is arranged so that at slow engine speeds, as at idling,fresh oil is pumped through the transmission units, available theinstant the engine starts up, since the main oil pump gear I 13 isconstantly driven from the main clutch driven shaft 5 through gears 1--IIi.

'lo relieve the driver or servicer from learning new modes of operation,I arrange the servo mechanism so that when the car is standing still,the driver may warm up a cold engine by holding the customary mainclutch pedal in disengaging position. I'his operation may be carried onwithout forcing oil unnecessarily through the servo system.

pump,.at any time when either engine or vehicle are in motion.`

The automatic speed ratio controls for the operation of the front unitcomprise, first, I'IU, moved by the governor toward the left in Figures,6 and 7 as engine speed increases, and pivoted to equalizer bar I I atI I2.

The opposite end of the equalizer bar is pivoted to toggle shifter rodI|3 at |36, and near its center, notch ||4 is engaged by pin ||5 set inlost motion lever I I6. The latter lever rotates on shaft I2!)4 as' acenter; carries spring stop ||1 and also arm |23.

Opposing spring stop I |9 is integral with lever I2 I, also rotatable onshaft |20, and having eyelet |21. Intermediate spring |25 transmits forces in compression between levers |2| and H6, the spring stops ||9 and||1 preventing thespring from leaving position.

Pin |I8 in lever |36 may engage eyelet |21 of lever |2| rotatable onshaft |20, the function of the eyelet being to provide lost motion orlimit it in the clockwise rotation of control shaft |20.

Adjustable stops |28 and IZB-mounted in compartment |24 are used tolimit the angular position of lever I2 I.

Lever |32 mounted external to the compartment |24, rotatable with shaft|20, is pivoted to rod 36| and |34, and responds to the acceleratorpedal movement.

At a given position of governor link pivot II2, lever |32 may rotateabout center |20 counterclockwise, rotating lever I3| and pin ||8causing arm |2| and spring stop ||9 to compress spring |25 applying anincreasing force to cause corresponding motion of I I6. Pin I I5thereupon exerts a leftward forceupon equalizer bar III, and on linklever |I3 attached to it at pivot |36.

An increase in governor speed will tend to shift 4.0 pivot |36 to theright, lever'l II fulcruming at II4,

The double pump system is a feature of my invention but not claimed inthe present application. Since shafts 5 and 8 may rotate at diiTerentspeeds, and in opposite relative directions, and since it is desirableto furnish oil pressure at all 1 times whenever any rotation whatever isimparted to the variable speed gearing; and further that it isadvantageous to arrange the mechanism so that no operators whim mayinterfere with the circulation of oil Whenever the related portions ofthe gearing may be rotating under either engine rotation or vehiclemotion, I have herein created an oil supply system fulfilling theserequirements by combining the vrotation of these shafts in a drivingsystem to a double unit pump of the augmenting type, staged for onerange of pressures for forward drive, and for another '.lange ofpressures for reverse drive,-yet provid# tending to counteract the abovementioned motion.

Casing extension |65 supports levers I38|39 at pivot |31.

on nxea pivot |31 .toggle arms las and Iss'are mounted, the lower arm|38 being attached to pvot coupling |40. The engaging end of link lever||3 coacts with coupling |40 assisted by spring |4| stressed betweenguide lug |43 and the pin |40 on link lever ||3. Thus a rightwardlyexerted force in rod ||3 acts on coupling |40 to cause arm |33 to swingcounterclockwise about fixed pivot |31.

'I'he upper arm |39 of the' toggle is yoked to valve body |50 by loosepivot |44, and also at its upper end, carries weighted pivot |45.

Toggle spring |48 attached to arms |38 and |39 at |49 and |45respectively, stores energy for snapping the valve right or left, aspivot |49 of arm |38 is moved past center with relationship to xed pivot|31 and pivot|45 of arm |39..

When valve body I 50 is in the right hand position as will be seenlater, fluid pressure is admitted to hold oi brake and engage the clutch33-36. of the front unit. When it is 'in the left hand position, the uidpressure of that system is released and the front unit is put in lowgear drive by springs 81-81a actuating brake band 80, through rod 280,rocker 393 and thrust rod similar to in Figure 4.

Plate |26 rotating with shaft |52 is rocked by movement of externallymounted lever |5I attached to shaft |52. The latter lever is joined torod 3|0 at pivot |53, and selection movement of hand lever 30| of Figure6 acts to shift lever I5| free and automatic shift action is resumed.

Irregular cam slot |55 cut in cam .plate |26 actuates the valve |68connected with theoperation of v the rear unit. Hook |56 acts as a stopengaging with toggle arm head |45 to prevent automatic shift to highratio in the front unit, when the plate |26 is in "reverse position.This is the automatic shift lockout mechanism.

Lever |60 pivoted at |58 moves manual valve |68 at yoke 298 and carriespin |59 which flts cam slot |55 of cam plate |26. The centers of |'52and |58 are taken with respect to the arm |58-|59 and the radii of slotdistances from center |52 so that movement of arm |5| by rod 3|0 forceslever |60 to follow clockwise motion of lever |5|, actuating manualvalve |68 of the rear unit, for shift to low, or counterclockwise forvdirect. Y

Valve |68 moved by lever |60 through yoke 298 follows the movement oflever |5|. The cam slot |55 which moves pin |59 of |60 is arranged toestablish the valve |68 in the following positions:

Pressure Halldshit Ratio Servo controls These control linkages may bemounted on the left side of the transmission casing superimposed uponthe valve casting, as indicated schematically with the governormechanism at the left; and at the right the toggle support |65 for pivot|31. The downward extension of the valve case casting terminates at theright in guide lugs |43, between which lever link I3 is constrained tomove. Pivot pin |58 projects toward the eye ofthe observer and is amounting forlever |69.

The manual control valve |68 moves in bore |61; uppermost port, 260,relieves fluid pressure from the cylindrical space 26|, dumping the oilback into the external portion of the housing, from whence it drainsback to the sump 2|9 of the transmission. The second port, 262, leads tothe outlet of the casing, from where the oil may flow, through line 212to the control cylinder 292 for the rear unit. The port 263 below is theinlet from the servo pump, and it receives oil from passage 213 throughthe porting shown. The port, 264, delivers fluid'pressure to passage211, from where it is used. to compensate -for brake releasin-g actionof springs 91 and 91a. Straps cover cylinders 282 and 292, as retainersfor the spring assemblies shown.

When the valve |68 is in the lowermost position, the pressure from theservo is admitted to port 264 and through 216--211 to cylinder 295, thuscompensating for existing line pressure in 219, for regulating thetorque capacity of clutch 55--60, as will be explained. When the valve|68 is in the upper position, it cuts off the pressure from the line262- 212 and drains ports 264 and 262. This is accomplished when thehand lever 30| is placed in either low or reverse" position on ltheindicator plate 302'. During downshift from direct to low, speed ratioin the rear unit, this port relationship is effective, but not when inneutral When the valve |68 is at the bottom of its stroke or in thedirect drive position fluid pressure from 263 is admitted to port 262,and is effective to overcome the force of springs 91-91tz exerted onbrake 90, as well as exert pressure upon clutch plates 55-60. Port 260is effective to drain the rear unit cylinder 292 through port 262 whenthe valve |68 is moved back to the low-speed position.

Clutch feed lines 218 and 219 are shown in the schematic view of Figure6.

Figures 6 and 8 show valve plunger |50 for the control of the front unitin closed position, with line 218and port 261 open to exhaust. Whenvalve |50 shifts to the right-hand position, the front unit will go todirect drive, the action causing engagement of clutch 33-36.

The mechanical movement which requires the valve to occupy the describedtwo positions is shown in Figure 6, where loose pin |44 connects theextension of valve |50 external to the case |6| to toggle levers|39-|38. The two-positional action of the toggle mechanism has beendescribed preceding.

Piston rod 290 works against rocker |93 pivoted 'at |94, movement ofrocker |93 exerting thrust on thrust arm |90, which is pivoted to thefree end of brake band 90 at 90a, and the reduced end of which swivelsin notch |92.

Rod 290 is `fastened to abutment member 296, which is apertured topermit passage through it of pins 291 attached to piston 294, wherebysliding abutment 214, on fixed abutment rod 300 may receive the motioncaused by uid pressure in 295 and 292.

Attention is directed to the construction of the actuation uni-ts shownin Figure 6. Springs 81, 81a, and 81b react against retainer strap 283bolted to cylinder 282, which may be integral with transmission case 2or the metal forming the compartment |24. Springs 81 and 81a exert theirtension against piston 28|, which may slide ffreely on rod 280. Spring81h normally exerts pressure against abutment member 288 raised to slideon stop rod 300 attached to cap 283. Abutment member 286 is rigidlyattached to the end of rod 280. and may bear against abutment member 288to the limit of motion allowed by the ends of rOdS 280 and 300.

' sure in clutch cylinders 1|.

Initial uid pressure admittedithrough pipe 215 to cylinder 282 may buildup rapidly, being assisted by the force stored in spring 284. When theface of piston 28| strikes the upper end of abutment 286 at point 286a,the two springs 81 and 81a are overcome and the initial positive imovement of the brake releasing system begins. The continuingapplication of uid pressure to cylinder 282 thereafter causes abutment286 to engage abutment 288, pressing spring 81h. Continued movement maytherefore take place until the shrouded end of rod 280 engages theadjacent end of fixed abutment rod 300.

Assuming that the servo pump may only deliver a finite pressure at anyone time, movement of valve |50 to a position to connect the pump withport 215 likewise affects the net pressures existing in line 218,available for loading pistons 12 and establishing drive in clutch 33-36of the iront unit. It will be understood that during the first phase ofpressure increase in cylinder 282, that the iirstl stage of pressureduring which spring 284 is loading piston 28| to move toward point 286eis the initial engagement stage of the clutch, during which a fairlyrapid building up of volume is accompanied by a gentle rise in pres-After the abutments 286 and 268 meet, the increase in pressure due tothe increased resistance of spring 81h now brought into play causes amore sudden building up of pressure on the clutch plates 33-36, so thata graduated and increasing clutch capacity can be created and sustainedduring the clutch engaging cycle when the brake release mechanism isoperative, and thereafter when the relative motion between the sets ofclutch plates ceases.

Port l262 connects pump line 213 and its port 263 with line 219 whenvalve |68 is in the "upposition of Figure 9. Port 260 opens to sumpthrough self-loaded valve (not numbered) afxed to the casing ofcompartment |24. Port 264 joins the lead 216 to compensator line 211 'ofthe rear unit, corresponding to port 261, which joins 216 to compensatorline 211 for the front unit.

In Figure 9 cam plate |26', similar to |26 of Figure 6, is mounted torotate freely on shaft |20, and is moved by lever 4|5 attached to theshaft, through spring 4|6 and lever 4|1 pivoted on the cam plate |26' at4|8'. Stop pins (not numbered) retain proper distance relationshipsbetween levers 4|5 and 4|1, which are bossed to hold the ends of spring4|6 in place.

Lever |35', moved by the governor, is arranged to transmit its motion tolever 420 which, in construction, may be integral with, or an extensionof |35', although in the schematic drawings, the two levers are shownseparate, joined by a shaft pivoted on the housing. When the governor tothe accelerator pedal 303. Fluid pressure from 212 and 219 is ledthrough ling4|0 to apertured bushing 4| and through line 4 2 cored anddrilled in lever ||6. v

Piston 4 3 receives uid pressure from this system, line 4|2 opening tocylinder 4|4 in which piston 4|3 is mounted, so that whenever the rearunit is in direct drive, the clearance distance between the end of leverI3 I and the base of piston 4 |3 becomes less, and the net distancemoved by the pedal connected lever |3| is less, before a resultingresponse of lever ||6 to pedal motion is had.

The passage of clutch fluid pressure from cylinder 282 of the front unitflows through 218, and 19 to cylinders 1| in drum 28. Likewise the nowfrom cylinder 292 of the rear unit passes through 212, 219, and 19' tocylinders 15 of drum 39.

Figure 4 is a transverse vertical section through the transmissionassembly. Drum 39 of the rear unit is shown in position to ybe grippedby brake band 90, the fixed end of which, 9|, is restrained fromclockwise movement by adjustable bolt 92 through the extension 'ofhousing 2. `The movable end 93 of band 90 is positioned by thrust rod|90, rocker |93 and the upper end of piston rod 290, which is attachedto piston 29| iitting into cylindrical recess 292 in the housing as inFigure 6. Springs 91 and 91a bear against the piston 29| in a directionto cause brake band 90 to grip drum 39 being supported by base or cap293. Subpiston 294 slides in compensating cylinder 295 under fluidpressure supplied from the differential valve 320 described following.The three conditions of operation of this structure are: rst, fluidpressure may be introduced against the head of p1ston 29| to counteractthe force 4of springs 91 and 91a and thereby release brake band 90 fromdrum 39; second, iiuid pressure admitted to subpiston cylinder 295 maychange the value of the line pressureat the moment when brake releaseoccurs; and third, the uid pressure may work simultaneously behind bothpistons 29| and 294, providing a low line pressure at the instantV ofbrake release, which acts to limit the clutch capacity since the degreeof line pressure governs the magnitude of clutch loading.

The latter expedient is to eliminate shock during ratio downshift atlight engine torques, and

mechanism goesto high speed position, levers f |35' and 420 rockcounter-clockwise until the flat end of 420 assumes a position to blockclockwise movement of lever 2|1. Should the operator attempt to shiftthe rear unit to low by movement of lever 30| of Figure 6, at a timewhen governor speed is upward of '10 miles per hour, for example, lever420 will abut leverv 4|1, and the cam plate |26' will not move, althoughthe handlever action will yield to the operators effort because ofspring 4|6.

Lost motion lever ||6" of Figure 9 is pivoted in the compartment |24 toswing in an arc to intersect the movement of lever |3| rocking withshaft |20 and lever |32 connected as in 'Figure 6,

to proportionalize torque capacity to torque demand. This effect is madepossible by the nature of the clutch construction described above inconnection with Fig. 5, since the provision of inherent rate control ofvariable clutch area with loading pressure, coupled with rapid releaseof torque when the clutch is unloaded both have time factors capable ofcoacting with the above control structure for attaining optimum engagingand release action. d

The diierential valve mechanism is housed in the casing 2 behind thecompartment |24, and consists of valve 320 integral with stem 32|,pressed toward its seat by spring 322 and plunger 323. the spring andplunger force being opposed by iiuid pressure, as will be describedfurther.

As shown in Figure 8, the Valve 320 is mounted to slide freely in bore 39, the extension 324 striking stop 325 at the upper limit of motion. Theupper end of bore 3 9 is enlarged to accommodate ported sleeve 326,which may slide therein. Flange 321 of sleeve 326 is pressed towardseating with the upper edge of valve 320, by spring 328 whose retainercap 329 fastened on the valve casing is of such inner diameter as tolimit the upaseaeao mdtravei ofsleeve 32|', which latteris a fom of.piston valve. l

Annuler recess 33,3 forms a lifter port for sleeve 326, whereby fluid.pressure :rom line 3.113 may oppose the prsure or spring 323, and changethe Y pottlopeninehetweenthe lower edge of. the sleeve 323 andr theupper face ofvalve 32l.

Transverse ports 33|; in sleeve 323 coincide generally with largeannular space 332y connecting to drilled passage 232, wherein :duidpressure from 232 may always he. onenk to space 333, between stop 323,the interior of: sleeve 323 and the upper tace of valve 333.

ouet space 334 is f smaller diameter than sleeve 3st, thus providing alimit or downward travel therefor. Space 33t is ported at 335 and 338,the passage 331 leading to counterbalencina annulus 33t; and the e 2libeing conn to the compensator chamber 2395 of the actuator for the rearunit.

Spced between annali 336 and 338 is the ex-y haast annulus 33t, forrelieveins excess pressure imm space 333. Cap 323 may beof threaded formwith relationship to casing 2, for variable adjustment ci the tension onspring 32|, in order to predetermine that pressure in line 3|! at whichsleeve 323 will rise, and, thereby establish thecleerance distancebetween sleeve 323 and valve 323 for closing o space 334 when valve 32uis moved by plunger 323.

The net tension in spring 322 determined by normal setting of lever |22against plunger 323 kand the degree of line pressurein space 334 fromlead 233, establishes the gradation characteristic in the building up oftion action by piston 336 in the control of line pressure in 219 andclown cyinders l5, as will be explained in the discussion following,descriptive or the clutch capacity control.

The construction of the brake-bands 8c and Se is identical.

The front unit parts in the brake actuation assembly are identical withthose of the rear unit, rocker 333 being the `same as rocker |93, there- :naming thrust rod and notch construction, like- Wise the same.Wherever possible, identifying numbers in series pertain to similar.parts having identical functions. It is not deemed necessary to vshow afull section of the brake actuation m of the front unit, because 0f theParallel identity oi the parts.

nacion sie is s spring-loaded latch, hand v operated. to hold lever 33|in any of its operation dote f ,i' positions.

Reciprocating motion .of the lever results in. correspondingreciprocation of the shifter .rod 368. pivots 393, 3i! ci lever |05. rodSID, and pivot |53 of lever iti as seen in Figures 6 and 7.

The transverse section of Figures 2 and 3 shows the governor drivemechanism, the gear 15 iixed to mit 3M meshing with gear H6 of shaft Thegovernor shaft 23| is supported in casing u .f and carries aihxed huh2M. Secured to flanged huh tot ere pins 245, each recessed under theheed et 333Mo engage spring retainer plate dol. Weight 2&8 are pivotedto huh 2M at 2o@ and terminate in cam ends 236 and weightlarsecoilspnallrestsasainst plate 2M andts aseatintheilanseoi hub 2M.Internal coil spring 25 likewise rests against retainer plate 2li' andpresses traveler sleeve 25|' to tlm lett. This sleeve 255 is. hallowedout to a hearing nt over the spindle end 255 of shaftlli andmayslidefreelyaxially,asthrust bytheendoi'springuactingonilaneeii.

vAt the external end of sleevel 255 collar 2W provides connecting meansfor the external mechanism to be moved by the governor, as indicated inFigure 6. Normally at rest, the ly of gov-r ernorpartsisasshowninhigure..esapplied speed increases, weights 25| of arms 2 swing about pivots 2l!and cam. ends 28| shirt sleeve :Il against the tension of spring 253.When the sleeve has moved a predetermined distance, the seat 233 of the:danse 353 of sleeve 255 shuts end of spring 252, and further increaseoi applied speed resulta in weights worms' against the combined stressesof springs 234 and 252. It will be seen that the relative travel ofsleeve 2551 for a given speed increment in the latter phase is less thanin the prior stage,v the governor working against an increasedresistance. Variations of governor speed above a predetermined point cancreate no change in the external control mechanism, when the weighhs251| stand atwlder angles to thecenterlineo theshatl.

The collar 253 is arranged. to move arm 359 xed to shaft 36| of Figure 6which latter moves arm 352 pivoted to governor rod H0 at 333. In thisway axial motion oi sleeve 253 is convertedto reciprocating motion ofgovernor rod H6, pivot ||2 and reciting of equalizer bar isaccomplished. .v

,The relationship of the accelerator pedal and handlever linkage are,shown inV Figure 6.

Accelerator pedal 333 is pivoted on the floorboard. of the driver-scompartment, and rod 355 is pi-voted at 35|? so as to be moved freely bythe pedal 363. Return spring 351 serves to restore the pedalV to minimumthrottle position. Connection 333 is to the engine throttle.

The bracket shown provides a pivot for shaft 858 and lever 353, the rod355 hooking into hole 363, and lever 333 being attached tothe shaft 358,and pivoted to rod 35| at 332. Depression of the accelerator pedal 303will therefore exert a thrust on rod. 355, lever 353 will swingclockwise, and consequently rod 36| will be pulled toward the left inmore 6. This action rocks lever |32 through tted pivot |34, and shaftcenter 62B, causing pin ,ils to engage eyelet 23, and rock lever l2!countercloolrwise. vllheriever spring |25 is so stressed, theimpulse ofthe drivers .foot is exerted to swing lever HE in the saine direction,

consequently to move pin als and bar Mi to the left. This is thedirection of movement to P1111 rod H3 to the left, which may through thetoggle mechanism i3d-|38 snap the valve i5@ controlling the front unitinto the low position. Whenever the accelerator pedal 383 is depressed,the described mechanism then establishes a'. tend- The followingassembly of parts are mounted on the transmission casing 2. Shaft |20,to which lever |32 is attached extends into the control compartment |24,where lever |3| is attached to the shaft. Levers ||6 and |2| may rotateon |20. Lever |3| carries pin ||8 which fits loosely in eyelet |21 oflever |2|, and carries extension arm |23, with cam follower |23'.

vAn adjustment placed at pivot 362'permits the service operator to setthe relationship between required motion of the pedal 303 for a giveneiiect on the mechanism controlled -by rod 36|, and that at 359'-363 maybe set to determine the movement of the engine throttle, so that apredetermined throttle pedal position provides a given stress of spring|25 followed by engagement of abutments ||9 and ||1 of the levers |2|and 6 to suit the engine torque-speed curve and the running resistanceof the vehicle. The adjustments may be set so as to require anypredetermined throttle opening before downshift occurs, and theadjustable stop system |28|29 enables the serv ice operator to vary therelative effect of the throttle motion upon the shift control.

In Figure 13 is shown a modification of the control structure of Figures6 and 7, wherein camplate |26" is arranged to occupy a position beyond'the high for enabling the car driver to enforce a downshift in the frontunit within predetermined operating speed ranges. Slot |55' in camplate|26 is extended to a new position such that it may rotatecounterclockwise between "H and 3rd without moving pin |59' of arm |60and therefore allow the rear unit valve |68 controlled by that arm toremain in the upper position-of feeding fluid pressure to the rear unit.

Extension |30 of camplate |26 rotates so as to intersect pin of lever|23, over the rounded surface of which it may exert a camming action,shifting the p in ||6 to the left, causing equalizer vbar to move to theleft an equivalent distance `ful for acceleration demand other thanprovided by throttle pedal interaction control with the governormechanism.

At speeds above 65 miles per hour, for example,

the governor may move pivot ||2 so far to the left that this enforceddownshift action cannot occur, and the drive will then remain in directin both units, with both clutches retaining their effective drivingtorque capacity.

'I'he modincation in the manual controls required to accommodate for theextra motion of the enforced third shift is shown in Figure .14, whereinsector plate 302 is extended to a new positiorrmarked Third 'Ihemovement of the hand lever 30| from H to the new position in no wayaffects the action ofthe valve |68 controlling the rear unit, since slot|56 of even radius with that of the slot |66 to the point where fluidpressure admission to the rear unit is established.

Controls similar to the above have been described and discussed 'in thepreceding cases noted in the superscription of the presentspeciflcation, l

The governor connected linkage has not, however, been put outv ofaction, but is still able to prevent abuse of engine and transmission,in that This yields a selective effect of engine braking andacceleration available to the car driver within definite speed ranges ofengine and vehicle, wherein neither engine nor transmission mechanismmay be abused, and permits the driver to establish a'xed reduction ratiofor gradient work where torque rather than fuel economy is desired.

It will be noted that after an excess speed upshift to High compelled bythe governor, when the setting is for enforced Third drive; the controlmechanism will reset to Third" when the governor speed falls, and drivein 'I'hird" will be resumed, requiring no' especial attention from thecar driver. Resumption of normal automatic shift in the automatic unitis accomplished by resetting the handlever in its High posi- The motionof the handlever 30| from Low" position to other sector required a lostmotion provision in the linkage of lever 308 to shaft |03, lever |02,and slider |04, so that after jaw clutches 1'-|9 are meshed, the motionof 30| position whence pump line pressure from 213 may flow to 212, andthence to brake piston 26| and clutch pistons 16 through the describedportings. The valve is shown in the down position in Figure 10, port 263from the pump line 212 being cut off, and line 21.2 being opened -toexhaust passage 260, and regulating valve attached at 260' to thecasing. Valve 260" is made of spring steel, of a vpredetermined ratecharacteristic,

such that its exposed area bears a calculated relationship, for thepurpose of controlling the released pressure flow, thereby regulatingthe rates of clutch release, and brake application in the rear unit.

Figure l1 is an enlarged view of the construction o f the plunger 323operated by throttle connected lever |22, for manipulating thedifierential valve 320. Abutment member 214 in Figure 9 works againstspring 91e under thrust from pin 29.1, similarly to the action of spring91o in Figure 6.

The external shell of plunger 323 is bored out internally to iit collarwasher 321 which may slide on the adjacent end of the stem 32| of valve320. 321 from further movement induced by tension in spring 322.

I'he first increment of accelerator pedal motion rocks lever |22counterclockwise. further c ompressing spring 322, opposing the force offluid pressure acting on the upper face of valve 320, resulting in agraduating of the orice between the lower lip of sleeve 326 and thevalve 220, thereby restricting the pressure flow from space 334 tooutlets 216-211 available to create pressure on counter piston 294 inthe cylinder space between abutment or wall 206 in cylinder 202.

At full pedal, the end of stem 32| meets the Lock ring 340 prevents thewasherI .output pressure. Ported space 885' is joined by lead 216' tocompensator lines 211 and 211', and is cross-connected to space 888' bypassage 881'. Spring 822' reacts between the lower face of valve 320',and the recessed portion of plunger 323', guided by stem 32| of the thevalve.

The compensator valve 820 serves the purpose of regulating the rate oftransfer of torque from the geared path of torque to the clutch coupledpath. It governs the degree of loading pressure on the clutch that istaking the drive,at the instant of brake release, as will be apparentfrom the foregoing description.

In starting, the engine idles at a given speed. With the handlever 88|in neutral position, the spinning clutch disc and drive gearing areseparated from the final drive. The operator may warm up the engine, theservo pump gear cir' culating the transmission case oil through thedescribed passages.

When it is desired to put the vehicle in motion,

.the customary clutch pedal, depressed h3' the foot, separates themating clutch plates, the operator shifts the handlever 80| .tocorrespond to neutral to low shift of plate |26 of Figure 6. At thispoint attention is directed to a valuable .adjunct for absorbing theinertia of the main clutch-driven plate and connected parts. In myconstruction, the arrangement of clutch driven shaft 5, gears 1. and I6,and servo pump, and automatic pressure valve 280, provides apredetermined back pressure when drive is romoved from this system byopening of the main clutch.

Spring 20| causes valve 200 to block the iiow of the pump, yet*permitting oil to flow to the transmission bearings. The reactivepressure is here used as a clutch brake to assist the synchronizationrequirements, to give a smooth transition from neutral to low, so thatjaw clutch 1 will reduce quickly to zero speed.

Assuming forward drive synchronized. as soon as the driver relaxes themain clutch pedal, en-

gine torque is delivered to shaft 8, and to the input annulus gear I2 ofthe front unit. The car load is assumed to be acting on carrier element22 connected to shaft 2| which is the output shaft of the front unit.

With load on carrier 22, and engine torque on gear |2, a force isapplied'to the sun gear 25 tending to give it a retrograde rotation.

sBrake band 88 of the front unit being normally stressed for locking bythe springs 81, is prevented from slipping and the retrograde motion isstopped as torque reaction begins.

Gear 25 cannot further rotate, and cage 22 moves inthe same direction asthe engine connected gear, the planets 24 moving orbitally androtationally, shaft 2| being driven at a ratioto engine speed,forwardly.

With springs 91 active to load band 88 of the rear unit for locking, theapplication of engine torque to shaft 2| -andload to output shaft 88gives rotation to shaft 50, which then applies torque to the final drivemechanism such as road wheels, tractor treads, air or ship propellersand the like; at low speed ratio, or reduction in both the front andrear units.

Overrunning torque when the throttle is rel i ilaxed,orwhenthe1oadisdrivingthe engine as on downgrades, is overcome bythe greater torque reaction force of the brake springs, therefore dragis prevented.

The application of compensating uid pressure to subpston 288 of Figure6, with the handlever 88| controlling valve |88 through the linkageshown, is such that ports 288 and 28d are connected whenever thehandlever 88| is placed in the "low" forward position. The sub-pistonalso serves yan additional purpose.

A similar sub-piston 288' is used to compensate for the action of thefront unit brake 80, as will be described further.

Overrunning torque is then prevented from skidding the brakes because ofthe excess loading capacity of springs 81 and 81. The car operator isthen free from any possibility oi coasting or freewheeling, and mymethod increases the factor of positive control under severe operatingconditions, therefore increasing safety. Engine braking in low gear isdesirable from the point of View of maneuverability in traic, since amore accurate control over the slow speed positioning of the vehicle issubject directly to accelerator pedal 803.

The idling gears are protected from racing during the forward drivingspeed change interval, since a predetermined value of torque is alwaysbeing delivered through brakes Sil-90 or clutches 88-88; 88-88 becauseof the time factors of the clutch-brake system and the overlappingcontrol action.

The driver may now drive at will with low` setting of lever 88| andstill obtain the advantages of automatic operation. Governor 25|- 285through connections 850, 85|, 852 and |||l may exert an influence on theratio control .mechanism of Figure 6. Here the equalizer bar onincreasing governor speeds is urged to move left and to swingcounterclockwise about ||8 as a fulcrum, lever |88 restricting themovement. At a given governor speed, equivalent to engine speed, thepivot point ||2 of bar shifts left, lever link ||8 shifts right, and thetoggle |88|88 snaps from left to right bias, causing valve |58 to moveto a position to connect ports 288 and 281. This delivers fluid pressurefrom main outlet 288 of the servo pump and automatic pressure valvesystem of Figure 12, to the head of piston 28| in cylinder 282 of thefront unit, and to passages 218 and 18 leading to pistons 12 incylinders 1| of this unit.

Piston 28| overcomes the pressure of spring 81, strikes abutment 288a ofrod 280, and disengages brake". Pistons 12 load presser plate 14 andpress the clutch discs 88-88 together, squeezing the clutch disengaaingsprings 88. The above described building up of torque capacity in theclutch prevents shock during this transition.

The transition from low to direct in the front unit has been made, andthe new ratio of drive is the reduction ratio of the rear unit only.

For conditions requiring acceleration, maneuvering. or unusual torquedemand, the handlever may be kept in the low" position indefinitely andthe mechanism will select upshift only in the front unit. depending ongovernor speed and throttleV pedal position, the latter providing meansto affect selectionthrough the linkage 8|I8,l 855,

' 888, 888, and 88| of Figure 6, and through lever |82, pinlll, arm 2|and spring |25, which latter forces lever ||8 and pin ||5 to the mostleftward position allowed by'pin ||8 bearing against the notch of leverl2 I,

Contfl; J Valternation of direct and reduction drive isat Thisinteraction is.so arranged'that for normal operation while in lowsetting of handlever 30|, the movement of pin to maximum allowed leftposition can force the automatic shift to low within the low speedranges of the governor only, which is a protection against unnecessary,longcontinued operation in the extreme low ratio gearmg.

Furthermore, the cam plate |28 so limits counterclockwise motion oflever |23 about shaft |20, that as soon as the front unit shifts bygovernor action to direct drive, the increase in governor speedresulting from the opened throttle carries pivot ||2 to the left so farthat the permitted maximum leftward movement of ||5 is not far enoughfor the driver, even by full depression of the accelerator pedal 303 tofurther enforce a downshift in the front unit.

Now if severe driving conditions or up-grades be met, the governorspeeds may be reduced far enough so that the mechanism will be urgedtoward downshift.

This speed range of control is governor managed up to approximately 12miles per hour, in which range it is not obedient to operator will toshift to a higher ratio.

One may determine this speed range by varying the strengths andadjustment of governor springs 252-254, spring |25, biasing spring |4|and toggle spring |48 of Figure 8 and the setting of the effectivelengths of the various rods, and lever linkages. At descending governorspeeds above car speeds of 8 miles per hour, this setting normallyrequires the front unit to remain in direct drive, under normaloperating conditions,

Having considered the automatic operation in one ratio range, theoperation in the second range as noted preceding will now be described.

The car operator in shifting the handlever to high position, may fulfillone of the stated objectives, which is to cause a nearly simultaneousbut actually sequential 'shift in both the front and rear units, so asto provide a smooth transition from one intermediate ratio to anadjacent intermediate ratio. l

After the arm |23 departs from the cam face of `cam plate |26, when thehandlever 30| is put in high position, 4the lever H6 being urgedcounterclockwise by spring |25 is not further restrained, and for givengovernor and throttle settings, may cause the valve to be moved to lowposition. approximately at the same time i as the valve `|58 i5 shiftedto its high position.

This is true, however, within a limited established governor range, andat or nearly full throttle pedal position of 303.

At increased governor speeds with relaxed` "2nd to direct; thatis, thevalve |88 only will move.

rIfhe cai-' operator after shifting to handlever `position marked Henters the new regime of With the handlever 30| in high, the

the control ofthe combined eiect of' governor throttle pedal 303 can nolonger enforce a shift to 3rd, or to reduction in the front unit.

Full depression of the accelerator pedal 302 when driving at below 59miles. per hour causes the arm 6 to move left using pivot ||2 as amomentary fulcrum, and move link lever I I3 left. snapping toggleISB-|39 left, and shifting valve |50 left, closing por-t 286 and openingports 268-269 connecting port 261 to the sump. This drains clutch'cylinders 1|, line 218, cylinder 282 and line 214; springs 81 applyingbrake 80 to drum 28; eventually stopping the rotation of the drum, andsungear 25 which'serves as the reaction element for the gearing of 4thefront unit, establishing thereupon the reduction drive. The foregoingdescribed quick release of the clutch at this point obviates undesiredplate drag or stumbling effects.

At all governor speeds above 59 miles per hour, the pivot point ||2 ismoved too far left for the pin H5 to further enforce a. downshift, sincelever I I6 is receiving the maximum effort deliverable by spring |25;the lever system |,2l-I I6 being prevented from further clockwiserotation by stop |28.

When the speed drifts below the given 59 miles per hour point, theability of pin ||5 to enforce a downshift is resumed, as will beunderstood from the foregoing description.

On severe up-grades which impose a heavy torque on the engine,registered as a decrease in governor speed, and with open throttlerecording the operators torque demand, the downshift will occur withinAa definite speed range such that smooth transition from direct toreduction in the front unit occurs, and such that the available ltorqueis in general proportional tothe torque demand. On level roads, therelative points of pivots ||2 and ||5 as mutually acting fulcra willtherefore determine a different response characteristic bythe enginespower to sustain a given speed for the existing load, conditioned by theaccelerator pedal position. On downgrades, with relaxed throttle, thegovernor action causes the front unit to go -to direct drive and remainthere over all driving lspeed ranges above a predetermined and selectedpoint of approximately 17 miles per hour. In the range of 17-59 miles anhour it is possible for the car ,driver to establish a, downshiftthrough acceleration demand set up by depressing the accelerator pedal203, or torque demand.

While it is useful for the governor mechanism to prevent a downshift inthe front unit above a predeterminedgspeed of 59 miles per hour, forexample, it is just as useful to apply a similar safeguard to the rearunit. Thev construction of Figure 9-shows arm |35 pivoted at |8| 'to thegovernor operated rod III, and to lever 428 fixed to shaft |35. Lever420 is arrangedto intersect lever 4|1pivoted on pin 4|! of camlplate|20. so that for governor speeds in excess of. a Predetermlned speed',for example, 40 miles per hour, a shift ofhandlever 38| to low" will notmove valve |58, but compress spring 4|. through lever'4ll.

-' whue the handlever itself may be moved, the' resistance of. spring4|8 is felt, against the hand, and the lever 4|! will moveclockwlse,'strelsing that spring without moving lthe valve |88. or thecamplatei. I i

The reaction of governor springs 282 and 204 in the'system comprisingsleeve 25|. 'collar 201, arm 350, shaft 88|,- arm 352, rod Ill, andnotch of lever III provides 'a yieldable system between weights 25|,andthe control parts moved by lccam plate |25 through slot |55 guidespin 59 of Y celerator pedal 903 and handlever Any governor forcetransmitted back through the control linkage to the accelerator pedal053, 'must pass through spring |25, therefore the operator can only feelthat force up to the limit of the inherent compression force of thespring.

The travel of lever |32 of Figure 7 with respect to lever |23 fromidling engine throttle position to the point where pin H8 begins tocause I2I to rock provides a range of exclusive engine throttle controlfor pedal 303 which may be adjusted to the power requirements, andguarantees suincient torque development before the automatic controlinteraction can be initiated. Beyond this point, the range of pedalmovement is always involved with change of. ratio except for thedescribed checks and stops.

The driver may shift the cam plate |28 from "high to low position at anytime, except when the governor is at high speed positions as notedabove. When this is done, valve |58 of the rear unit is moved down as inFigure 6, connecting ports 253 and 254, and venting port line 212,cylinder 292, line 219, and cylinders 15 of the rear unit. When thepedal is depressed, the lever I3I is rotated until pin ||5 forces arm|2| to move counterclockwlse against spring |25, causing pin |I5 to takea position toward the left as in'Flgure 7, establishing a coupledrelationship between pin I5 and notch |I4-, limiting the leftward pointwhere the governor forces might exert an influence for upshift. When thehandlever is placed in the neutral position, the gear 'I9 andteeth I9'slide to a non-driving point, and valve |55 moves to direct driveposition for the rear unit.

Upon shifting to reverse, the main clutch pedal is depressed, applyingthe reactive fluid pressure load of the pump and lubrication system aspreviously described, to absorb the inertias of the rotating parts, andgear I9 is moved along helical splines 9 from right to left as in Figure1.

The slider IMfthrough cam 3|2 on arm |02 traverses along rod |0I nxed tothe casing, and the arm |00 moves gear I9 from right to left into meshwith idler gear I5. In shifting from reverse to neutral, the slidinggear I9 is demeshed from 5.

For ordinary passenger car work it is desired that drive in reverseshall be at only one reduction speed, whereas in various draft gear,logging engines, military tanks, excavators and the like it may beuseful to arrange the transmission and controls so that the samerange-of variable speed ratios are available in forward and reversedrive, while the present application relates particularly to passengervehicles in the examples. Therefore I show means to prevent theautomatic shift from taking place when the handlever 30| is put in"reverse, and drive can only be in reverse at low ratios in both units.

When cam plate |25 is in reverse position, hook |55, of Fig. '7` swingsto prevent arm |39 of Fig. 8 and pivot I 45 from moving to the right,preventing valve |50 from being moved to the right to direct driveposition for the front unit. The governor and throttle linkage cannotnow operate toggle ||39 with valve |50 locked in low position. As soonas the handlever is moved from reverse," hook |55 no longer restrainsar'm |39.

If an automatic ratio increase is desired for reverse, finger |55 may beomitted, and at a given governor speed, the front unit will change fromlow todirect drive. During reverse shift, the

lever |51 to rock lever |59 and valve |68 to its' limit of clockwisetravel, lifting. valve |55 so that servo pressure from line 238 throughport 2S@ cannot ilow to port 252, so that the springs 91 are active tolock brake of the rear unit.

The scope of my invention is believed to be broader than the specificexamples of application described herein, since many of the details maybe modified in many ways within the skill of one versed in the art.

The utility of my invention is in no way circumscribed to thedemonstration herewith given, i. e., an automobile power control device,but its applicability to excavators, hoists, tractors and similarmachines, machine tool drive, power 'shafting of boats, rail cars, andaeronautical vehicles is expressly stated herewith. The scope of myinvention will be apparent in the statements of the appended claims.

I claim:

l. In power clutch mechanism for vehicles, in combination, a primaryclutch member composed of multiple plates, a .secondary clutch membercomposed of multiple plates interleaved with the plates of said rstnamed member, the plates of said primary member being uniformlychanneled on both faces, the plates of said secondary member beingpretensioned in -conoidal shape, unloading means arranged to exert axialforce tov separate said members, and loading means adapted to overcomesaid unload means while supplyina graduated loading force.

2. In power clutch mechanism for motor vehicles, in combination,aprimary clutch member composed of multiple plates, a secondary clutchmember composed of multiple plates interleaved with the plates of saidfirst named member, said nrst named plates being provided with channeledspaces on the engaging faces, the plates of said secondary member beingpretensioned in dlscoidal shape, unloading means arranged to exert axialforce to separate said members, and loading means adapted toovercomesaid unloading means while supplying graduated loading force.

3. In clutching devices for motor vehicle transmissions, in combination,driving and driven members, a. clutch plate comprising a disc'having twodriving faces, slots in said disc arranged to cause said plate to rotatewith one of the members, grooving in both faces of said disc describedfrom its center, a second clutch plate adapted to rotate with the otherof said members comprising a disc mating wlth'said first named dischaving two faces, one of which is adapted to engage one of the faces ofsaid first named plate, said disc being pre-tensioned in conoidal form,means to lubricate the engaging faces of said plates, and loading meanscontrolling the drive of said plates operative to atten the disc of saidsecond named clutch plate wherebylubricant is squeezed out of the spacebetween the 'engaging faces into said grooving.

4. In transmission drive apparatus for motor vehicles, in combination, adisc clutch comprising two forms of torque sustaining elements, the rstof which consists of a grooved disc, the second of which consists of aconoidal disc mating therewith, unloading means tending to disengagesaid elements, and loading means arranged to flatten said conoidal discinto full contact with. said grooved disc through predeterminedgraduation o applied pressure by said loading means.

, 5. In transmission clutching mechanisms, m combination, driving'anddriven members, inter-

